Apparatus and method for encoding and decoding using polar code in wireless communication system

ABSTRACT

The disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure relates to encoding and decoding by using a polar code in a wireless communication system, and an operation method of a transmission-end apparatus includes determining segmentation and the number of segments, based on parameters associated with encoding of information bits, encoding the information bits according to the number of check bits, and transmitting the encoded information bits to a reception-end apparatus.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application a continuation application of prior application Ser.No. 17/322,119, filed on May 17, 2021, which is a continuationapplication of prior application Ser. No. 16/376,485, filed on Apr. 5,2019, which has issued as U.S. Pat. No. 11,012,185 on May 18, 2021 andwas based on and claimed priority under 35 U.S.C. § 119(a) of a Koreanpatent application number 10-2018-0039870, filed on Apr. 5, 2018, in theKorean Intellectual Property Office, the disclosure of which isincorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates to a wireless communication system. Moreparticularly, the disclosure relates to an apparatus and method forencoding and decoding using a polar code in a wireless communicationsystem.

2. Description of the Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4th generation (4G) communication systems, efforts havebeen made to develop an improved 5th generation (5G) or pre-5Gcommunication system. Therefore, the 5G or pre-5G communication systemis also called a ‘beyond 4G network’ or a ‘post long-term evolution(LTE) system’. The 5G communication system is considered to beimplemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, soas to accomplish higher data rates. To decrease propagation loss of theradio waves and increase the transmission distance, the beamforming,massive multiple-input multiple-output (MIMO), full dimensional MIMO(FD-MIMO), array antenna, an analog beam forming, large scale antennatechniques are discussed in 5G communication systems. In addition, in 5Gcommunication systems, development for system network improvement isunder way based on advanced small cells, cloud radio access networks(RANs), ultra-dense networks, device-to-device (D2D) communication,wireless backhaul, moving network, cooperative communication,coordinated multi-points (CoMP), reception-end interference cancellationand the like. In the 5G system, hybrid frequency shift keying (FSK) andquadrature amplitude modulation (QAM) (FQAM) and sliding windowsuperposition coding (SWSC) as an advanced coding modulation (ACM), andfilter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA),and sparse code multiple access (SCMA) as an advanced access technologyhave been developed.

The Internet, which is a human centered connectivity network wherehumans generate and consume information, is now evolving to the internetof things (IoT) where distributed entities, such as things, exchange andprocess information without human intervention. The internet ofeverything (IoE), which is a combination of the IoT technology and thebig data processing technology through connection with a cloud server,has emerged. As technology elements, such as “sensing technology,”“wired/wireless communication and network infrastructure,” “serviceinterface technology,” and “Security technology” have been demanded forIoT implementation, a sensor network, a machine-to-machine (M2M)communication, machine type communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. IoT maybe applied to a variety of fields including smart home, smart building,smart city, smart car or connected cars, smart grid, health care, smartappliances and advanced medical services through convergence andcombination between existing information technology (IT) and variousindustrial applications.

In line with this, various attempts have been made to apply 5Gcommunication systems to IoT networks. For example, technologies such asa sensor network, MTC, and M2M communication may be implemented bybeamforming, MIMO, and array antennas. Application of a cloud radioaccess network (RAN) as the above-described Big Data processingtechnology may also be considered to be as an example of convergencebetween the 5G technology and the IoT technology.

The use of a polar code in the 5G system has been discussed. The polarcode proposed by Arikan is the first error correcting code theoreticallyproven to achieve channel capacity. A concatenated outer code is usedfor encoding and decoding information bits using the polar code, and theconcatenated outer code may include an error detection code such as acyclic redundancy check (CRC) code, an error-correcting code such as aparity check code, and the like. As the use of the polar code isdiscussed, a method for improving the encoding and decoding processesperformed using the polar code is needed.

The above information is presented as background information only toassist with an understanding of the disclosure. No determination hasbeen made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the disclosure is to providea method and an apparatus for effectively performing encoding anddecoding using a polar code in a wireless communication system.

Another aspect of the disclosure is to provide a method and an apparatusfor stably and efficiently performing encoding and decoding using apolar code in a wireless communication system.

Another aspect of the disclosure is to provide a method and an apparatusfor determining the number of segmentations in a wireless communicationsystem.

Another aspect of the disclosure is to provide a method and an apparatusfor determining whether to perform segmentation in a wirelesscommunication system.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to various embodiments of the disclosure, a method oftransmitting a signal by a terminal in a wireless communication systemmay include generating a bit sequence; determining to perform a codeblock segmentation for the bit sequence based on a number of bits of thebit sequence being larger than or equal to a first value; generating aplurality of segments by performing the code block segmentation to thebit sequence; generating a coded bit by encoding the plurality ofsegments; and transmitting, to a receiving apparatus, the coded bit.

According to various embodiments of the disclosure, a terminal oftransmitting a signal in a wireless communication system may include atransceiver configured to transmit and receive a signal; and acontroller coupled with the transceiver and configured to generate a bitsequence, determine to perform a code block segmentation for the bitsequence based on a number of bits of the bit sequence being larger thanor equal to a first value, generate a plurality of segments byperforming the code block segmentation to the bit sequence, generate acoded bit by encoding the plurality of segments, and transmit, to areceiving apparatus, the coded bit.

According to various embodiments of the disclosure, a method ofreceiving a signal by a base station in a wireless communication systemmay include receiving, from a transmitting apparatus, a coded bit;determining that a code block segmentation was performed to the codedbit based on a number of bits of a bit sequence for the coded bit beinglarger than or equal to a first value; generating a plurality ofsegments by performing the code block segmentation; and obtaining thebit sequence by decoding the plurality of segments.

According to various embodiments of the disclosure, a base station ofreceiving a signal in a wireless communication system may include atransceiver configured to transmit and receive a signal; and acontroller coupled with the transceiver and configured to receive, froma transmitting apparatus, a coded bit, determine that a code blocksegmentation was performed to the coded bit based on a number of bits ofa bit sequence for the coded bit being larger than or equal to a firstvalue, generate a plurality of segments by performing the code blocksegmentation, and obtain the bit sequence by decoding the plurality ofsegments.

The apparatus and method according to various embodiments of thedisclosure can improve decoding performance in case of constructing thepolar code.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communication system according to variousembodiments of the disclosure;

FIG. 2 illustrates a configuration of a transmission-end apparatus in awireless communication system according to various embodiments of thedisclosure;

FIG. 3 illustrates a configuration of a reception-end apparatus in awireless communication system according to various embodiments of thedisclosure;

FIG. 4 illustrates a functional configuration of a transmission-endapparatus that performs encoding in a wireless communication systemaccording to various embodiments of the disclosure;

FIG. 5 illustrates a functional configuration of a reception-endapparatus that performs decoding in a wireless communication systemaccording to various embodiments of the disclosure;

FIG. 6 is a diagram illustrating a polar coding process in a wirelesscommunication system according to various embodiments of the disclosure;

FIG. 7 is a diagram illustrating polar coding and segmentation in awireless communication system according to various embodiments of thedisclosure;

FIG. 8 is a diagram illustrating decoding performance in a wirelesscommunication system according to various embodiments of the disclosure;

FIG. 9 is a diagram illustrating performance variations at various coderates in a wireless communication system according to variousembodiments of the disclosure;

FIG. 10 illustrates a flow diagram of a transmission-end apparatus thatperforms encoding by using a polar code in a wireless communicationsystem according to various embodiments of the disclosure;

FIG. 11 illustrates a flow diagram of a reception-end apparatus thatperforms decoding by using a polar code in a wireless communicationsystem according to various embodiments of the disclosure;

FIG. 12 illustrates a functional configuration of a reception-endapparatus that performs decoding in a wireless communication systemaccording to various embodiments of the disclosure;

FIG. 13 illustrates a flow diagram of a reception-end apparatus thatperforms decoding by using a polar code in a wireless communicationsystem according to various embodiments of the disclosure;

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thedisclosure. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of thedisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of thedisclosure is provided for illustration purpose only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

For the same reason, some elements in the drawings are exaggerated,omitted, or schematically illustrated. Also, the size of each elementdoes not entirely reflect the actual size. In the drawings, the same orcorresponding elements are denoted by the same reference numerals.

The advantages and features of the disclosure and the manner ofachieving them will become apparent with reference to the embodimentsdescribed in detail below and with reference to the accompanyingdrawings. The disclosure may, however, be embodied in many differentforms and should not be construed as being limited to the embodimentsset forth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete and will fully convey the scopeof the disclosure to those skilled in the art. To fully disclose thescope of the disclosure to those skilled in the art, the disclosure isonly defined by the scope of claims.

It will be understood that each block of the flowchart illustrations,and combinations of blocks in the flowchart illustrations, may beimplemented by computer program instructions. These computer programinstructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which are executed via the processor of the computer or otherprogrammable data processing apparatus, generate means for implementingthe functions specified in the flowchart block or blocks. These computerprogram instructions may also be stored in a computer usable orcomputer-readable memory that may direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer usable orcomputer-readable memory produce an article of manufacture includinginstruction means that implement the function specified in the flowchartblock or blocks. The computer program instructions may also be loadedonto a computer or other programmable data processing apparatus to causea series of operational operations to be performed on the computer orother programmable apparatus to produce a computer implemented processsuch that the instructions that are executed on the computer or otherprogrammable apparatus provide operations for implementing the functionsspecified in the flowchart block or blocks.

In addition, each block of the flowchart illustrations may represent amodule, segment, or portion of code, which comprises one or moreexecutable instructions for implementing the specified logicalfunction(s). It should also be noted that in some alternativeimplementations, the functions noted in the blocks may occur out of theorder. For example, two blocks shown in succession may in fact beexecuted substantially concurrently or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved.

The term “unit,” as used herein, may refer to a software or hardwarecomponent or device, such as a field programmable gate array (FPGA) orapplication specific integrated circuit (ASIC), which performs certaintasks. A unit may be configured to reside on an addressable storagemedium and configured to execute on one or more processors. Thus, amodule or unit may include, by way of example, components, such assoftware components, object-oriented software components, classcomponents and task components, processes, functions, attributes,procedures, subroutines, segments of program code, drivers, firmware,microcode, circuitry, data, databases, data structures, tables, arrays,and variables. The functionality provided for in the components andunits may be combined into fewer components and units or furtherseparated into additional components and modules. In addition, thecomponents and units may be implemented to operate one or more centralprocessing units (CPUs) in a device or a secure multimedia card.

Terms used in this disclosure are used only to describe certainembodiments and may not be intended to limit the scope of otherembodiments. The singular expressions may include plural expressionsunless the context clearly dictates otherwise. Terms used herein,including technical or scientific terms, may have the same meaning ascommonly understood by one of ordinary skill in the art. Among termsused herein, terms defined in a generic dictionary may be interpreted ashaving the same or similar meaning as the contextual meanings of therelated art and, unless explicitly defined herein, may not beinterpreted as ideally or excessively formal sense. In some cases,terms, even defined herein, are not construed to exclude embodiments ofthe disclosure.

In various embodiments of the disclosure described below, ahardware-based approach is illustrated by way of example. However, suchembodiments may include techniques that use both hardware and software,so that a software-based approach is not excluded from variousembodiments.

The disclosure relates to an apparatus and method for encoding anddecoding using a polar code in a wireless communication system. Inparticular, this disclosure describes a technique for determining thenumber of parity check bits, based on parameters associated withencoding and decoding of information bits in a wireless communicationsystem.

Hereinafter, a term referring to parameters, a term referring toinformation bits, a term referring to a channel, a term referring tocontrol information, a term referring to network entities, a termreferring to a component of an apparatus, etc. are used for convenienceof explanation. Accordingly, the disclosure is not limited to thefollowing terms, and other terms having equivalent technical meaningsmay be used alternatively.

Further, the disclosure describes various embodiments using terms usedin some communication standards (e.g., 3rd generation partnershipproject (3GPP)), but this is merely exemplary. Various embodiments ofthe disclosure may be easily modified and applied in other communicationsystems as well.

Generally, when data is transmitted or received between a transmitterand a receiver in a communication system, data errors may occur due tonoise existing in a communication channel. An error-correcting codingscheme is designed for a receiver to correct an error generated by acommunication channel Such an error-correcting code is also referred toas channel coding. An error-correcting coding technique is a techniquefor adding a redundant bit to data to be transmitted.

There are various schemes for the error-correcting coding technique. Forexample, a convolutional coding scheme, a turbo coding scheme, alow-density parity-check (LDPC) coding scheme, and a polar coding schemehave been known in the art.

Among them, polar codes are the first codes which are theoreticallyproven to achieve point-to-point channel capacity by using channelpolarization phenomena. The polar codes allow a code design optimizedfor each channel or code rate with density evolution, Gaussianapproximation (GA), reciprocal channel approximation (RCA), and thelike.

Among these error-correcting coding schemes, a polar code is the firstcode which is theoretically proven to achieve the point-to-point channelcapacity with low decoding complexity by using the channel polarizationphenomenon occurring in the successive cancellation (SC) decoding. Inaddition, it is confirmed that the polar code is excellent in practicalperformance as well as in theoretical performance. Especially, in caseof using SC-list (SCL) decoding with a concatenated outer code such as acyclic redundancy check (CRC) code, it is confirmed that the polar codehas superior performance compared with other channel codes. Accordingly,it was agreed to use the polar code when transmitting controlinformation via a control channel in the 3GPP Release-15 new radio (NR).

The polar code is an error-correcting code proposed by E. Arikan in 2008and the first error-correcting code which is proven to achieve thechannel capacity (i.e., data transmission limit) in all binary discretememoryless channels (B-DMCs) while having low encoding/complexityperformance. Compared to other channel capacity-approaching codes suchas a turbo code and a LDPC code, the polar code has advantages inerror-correcting performance and decoding complexity when short-lengthcodes are transmitted. Therefore, in 2017, the polar code has beendetermined to be used for transmission of short-length controlinformation in the 3GPP NR standardization for the 5G mobilecommunication.

The disclosure relates to error-correcting codes for correcting andrestoring errors and losses which occur or are likely to occur due tovarious causes such as noise and interference in a process oftransmitting or storing data. Specifically, the disclosure relates toencoding and decoding of a polar code, and also relates to an apparatusand method for more efficiently encoding and decoding information in aprocess of transmitting and receiving information in a mobilecommunication system and a broadcasting system.

FIG. 1 illustrates a wireless communication system according to variousembodiments of the disclosure.

Referring to FIG. 1 , a transmission-end apparatus 110 and areception-end apparatus 120 as parts of nodes using a radio channel in awireless communication system 100 are shown. Although FIG. 1 shows onetransmission-end apparatus 110 and one reception-end apparatus 120, aplurality of transmission-end apparatuses or a plurality ofreception-end apparatuses may be included. In addition, even though thetransmission-end apparatus 110 and the reception-end apparatus 120 aredescribed herein as separate entities for convenience of explanation,the functions of the transmission-end apparatus 110 and thereception-end apparatus 120 may be changed. For example, in an uplink ofa cellular communication system, the transmission-end apparatus 110 maybe a terminal, and the reception-end apparatus 120 may be a basestation. In case of a downlink, the transmission-end apparatus 110 maybe a base station, and the reception-end apparatus 120 may be aterminal.

In some embodiments, the transmission-end apparatus 110 may determinethe number of parity check bits, based on parameters associated withencoding of information bits, encode the information bits according tothe number of parity check bits, and transmit the encoded informationbits to the reception-end apparatus 120. In some embodiments, thereception-end apparatus 120 may receive the encoded information bitsfrom the transmission-end apparatus 110, determine the number of paritycheck bits, based on parameters associated with decoding of theinformation bits, and decode the information bits according to thenumber of parity check bits.

FIG. 2 illustrates configuration of a transmission-end apparatus in awireless communication system according to various embodiments of thedisclosure. The configuration illustrated in FIG. 2 can be understood ascomponents or elements of the transmission-end apparatus 110. Suchcomponents or elements refer to units for processing at least onefunction or operation and may be implemented by hardware or acombination of hardware and software.

Referring to FIG. 2 , the transmission-end apparatus 110 may include acommunication circuit 210, a memory 220, and a controller 230.

The communication circuit 210 may perform functions for transmitting andreceiving a signal through a radio channel. For example, thecommunication circuit 210 may perform a function of converting abaseband signal and a bit sequence in accordance with a physical layerstandard of a system. For example, in case of data transmission, thecommunication circuit 210 may generate complex symbols by encoding andmodulating a transmission bit sequence. Also, in case of data reception,the communication circuit 210 may recover a reception bit sequence bydemodulating and decoding a baseband signal. In addition, thecommunication circuit 210 may up-convert a baseband signal to a radiofrequency (RF) band signal and then transmit the RF signal through anantenna, or down-convert an RF band signal received through an antennato a baseband signal.

For the above, the communication circuit 210 may include a transmissionfilter, a reception filter, an amplifier, a mixer, an oscillator, adigital-to-analog converter (DAC), an analog-to-digital converter (ADC),and the like. Also, the communication circuit 210 may include aplurality of transmission/reception paths. Further, the communicationcircuit 210 may include at least one antenna array composed of aplurality of antenna elements. In view of hardware, the communicationcircuit 210 may be composed of a digital unit and an analog unit. Theanalog unit may be divided into a plurality of sub-units according tooperation power, operation frequencies, or the like.

The communication circuit 210 transmits and receives a signal asdescribed above. Accordingly, the communication circuit 210 may bereferred to as a transmitter, a receiver, or a transceiver. In thefollowing description, transmission and reception performed via a radiochannel are used as meaning including that the above-describedprocessing is performed by the communication circuit 210. Also, thecommunication circuit 210 may further include a backhaul communicationpart for communicating with other network entities connected through abackhaul network.

The communication circuit 210 may include an encoder 212 to performencoding according to various embodiments of the disclosure. Thecommunication circuit 210 may encode information bits to be transmitted,based on the number of parity check bits determined through thecontroller 230.

The memory 220 may store a basic program, an application program,setting information, and/or data which are required for the operation ofthe transmission-end apparatus 110. The memory 220 may be composed of avolatile memory and/or a nonvolatile memory. The memory 220 may providethe stored program, information and/or data at the request of thecontroller 230.

The controller 230 may control the overall operations of thetransmission-end apparatus 110. For example, the controller 230 maytransmit and receive a signal through the communication circuit 210. Inaddition, the controller 230 may write or read data into or from thememory 220. The controller 230 may include at least one processor ormicroprocessor, or may be a part of a processor. The controller 230 maycontrol the operation of components included in the communicationcircuit 210.

According to various embodiments, the controller 230 may include asegmentation determiner 232. The segmentation determiner 232 maydetermine whether to perform segmentation, based on at least one of thenumber of information bits, the number of encoding bits, and the numberof CRC bits. Also, the segmentation determiner 232 may determine thenumber of segmentations, based on at least one of the number of encodingbits and the number of CRC bits. The controller 230 may control thecommunication circuit 210 to encode the information bits according tothe determined number of parity check bits and transmit the encodedinformation bits to a reception-end apparatus. In addition, thecontroller 230 may control the transmission-end apparatus to performoperations according to various embodiments to be described below.

FIG. 3 illustrates configuration of a reception-end apparatus in awireless communication system according to various embodiments of thedisclosure. The configuration illustrated in FIG. 3 can be understood ascomponents or elements of the reception-end apparatus 120. Suchcomponents or elements refer to units for processing at least onefunction or operation and may be implemented by hardware or acombination of hardware and software.

Referring to FIG. 3 , the reception-end apparatus 120 may include acommunication circuit 310, a memory 320, and a controller 330.

The communication circuit 310 may perform functions for transmitting andreceiving a signal through a radio channel. For example, thecommunication circuit 310 may perform a function of converting abaseband signal and a bit sequence in accordance with a physical layerstandard of a system. For example, in case of data transmission, thecommunication circuit 310 may generate complex symbols by encoding andmodulating a transmission bit sequence. Also, in case of data reception,the communication circuit 310 may recover a reception bit sequence bydemodulating and decoding a baseband signal. In addition, thecommunication circuit 310 may up-convert a baseband signal to a RF bandsignal and then transmit the RF signal through an antenna, ordown-convert an RF band signal received through an antenna to a basebandsignal.

For the above, the communication circuit 310 may include a transmissionfilter, a reception filter, an amplifier, a mixer, an oscillator, a DAC,an ADC, and the like. Also, the communication circuit 310 may include aplurality of transmission/reception paths. Further, the communicationcircuit 310 may include at least one antenna array composed of aplurality of antenna elements. In view of hardware, the communicationcircuit 310 may be composed of a digital unit and an analog unit. Theanalog unit may be divided into a plurality of sub-units according tooperation power, operation frequencies, or the like.

The communication circuit 310 transmits and receives a signal asdescribed above. Accordingly, the communication circuit 310 may bereferred to as a transmitter, a receiver, or a transceiver. In thefollowing description, transmission and reception performed via a radiochannel are used as meaning including that the above-describedprocessing is performed by the communication circuit 310. Also, thecommunication circuit 310 may further include a backhaul communicationpart for communicating with other network entities connected through abackhaul network.

The communication circuit 310 may include a decoder 312 to performdecoding according to various embodiments of the disclosure. Thecommunication circuit 310 may decode received information bits, based onthe number of parity check bits determined through the controller 330.

The memory 320 may store a basic program, an application program,setting information, and/or data which are required for the operation ofthe reception-end apparatus 120. The memory 320 may be composed of avolatile memory and/or a nonvolatile memory. The memory 320 may providethe stored program, information and/or data at the request of thecontroller 330.

The controller 330 may control the overall operations of thereception-end apparatus 120. For example, the controller 330 maytransmit and receive a signal through the communication circuit 310. Inaddition, the controller 330 may write or read data into or from thememory 320. The controller 330 may include at least one processor ormicroprocessor, or may be a part of a processor. The controller 330 maycontrol the operation of components included in the communicationcircuit 310.

According to various embodiments, the controller 330 may include asegmentation determiner 332. The segmentation determiner 332 maydetermine whether to perform segmentation, based on at least one of thenumber of information bits, the number of encoding bits, and the numberof CRC bits. Also, the segmentation determiner 332 may determine thenumber of segmentations, based on at least one of the number of encodingbits and the number of CRC bits. The controller 330 may control thecommunication circuit 310 to receive the encoded information bits from atransmission-end apparatus and decode the encoded information bitsaccording to the determined number of parity check bits. In addition,the controller 330 may control the reception-end apparatus to performoperations according to various embodiments to be described below.

FIG. 4 illustrates a functional configuration of a transmission-endapparatus that performs encoding in a wireless communication systemaccording to various embodiments of the disclosure. The configurationshown in FIG. 4 may be understood as a part of the communication circuit210 of the transmission-end apparatus 110 shown in FIGS. 1 and 2according to various embodiments of the disclosure.

Referring to FIG. 4 , the transmission-end apparatus 110 may include asegmentation 402, an outer coder 404, an encoding input sequence mapper406, a polar encoder 408, a rate matcher 410, and a segment concatenator412 according to various embodiments of the disclosure.

In some embodiments, some of the above components may be omitted or anyother component may be added, based on system requirements or the like.The number of information bits to be transmitted by the transmission-endapparatus may be denoted by “A,” and the number of codeword bitspolar-coded and transmitted via a channel may be denoted by “E.”

In some embodiments, the transmission-end apparatus 110 generates aninformation bit sequence. For example, the transmission-end apparatus110 inputs an information bit sequence i={i₀, i₁, . . . i_(A)} 401 to betransmitted into the segmentation 402. This information bit sequence issegmented into a plurality of segments, as needed, by the segmentation402. The segmented information bit sequence b={b₀, b₁, . . . , b_(K−1)}403 is inputted into the outer coder 404. Hereinafter, for the sake ofconvenience, in the outer coder 404, the encoding input sequence mapper406, and the polar encoder 408, the r-th information bit sequencecorresponding to the r-th segment will be described as an example. Theouter coder 404 may outer-encode the input information bit sequence “b”403. For example, the outer coder 404 may encode an input informationbit sequence “b” 403 to improve performance. Such outer coding may beused to improve the performance of a maximum likelihood (ML)-likedecoder that performs decoding in consideration of a plurality ofcodeword candidates, as in SCL decoding or SC-stack (SCS) decoding of apolar code. In some embodiments, an error detection code such as a CRCcode or an error correction code such as a Bose-Chaudhuri-Hocquenghem(BCH) code and a parity check code may be used as an outer code. Onlyone outer code may be used, or two or more outer codes may be used incombination. In some embodiments, the length of the entire parity bitgenerated by one or more outer codes may be denoted by “L,” and a bitsequence generated as a result of outer coding may be expressed asb′={b′₀, b′₁, . . . , b′_(K+L−1)}. According to another embodiment, whenno outer coding is considered, L is 0, b′ is equal to b, and the outercoder 404 may be omitted.

The encoding input sequence mapper 406 may map the bit sequence 405,generated as a result of the outer coding, to a bit sequence 407 forpolar encoding. That is, for pole-coded encoding of the bit sequence407, the encoding input sequence mapper 406 may map or allocate the bitsequence b′ 405 to a bit sequence u={u₀, u₁, . . . , u_(N−1)} 407 havinga length N. In some embodiments, N, which is the size of a mother codeof a polar code, may be represented as a power of two, and may bedetermined by a predetermined criterion from among values greater thanthe sum of the information bit and the length of the entire parity bitgenerated by the outer code. In some embodiments, the bit sequence u 407is an input bit sequence of the polar encoder 408, and bits of theoutput bit sequence b′ 405 of the outer coder 404 may be mapped to thebit sequence u 407 according to a predetermined method and criterion.The above-described mapping method may be performed in consideration ofa rate-matching operation to be performed later. As an example, in caseof the 3GPP Release-15 NR code, a bit index of the bit sequence u 407 towhich each bit of the output bit sequence b′ 405 are mapped ispredefined in the form of a sequence. Each bit of the encoding input bitsequence obtained by this operation may be interpreted as if it passesthrough split channels or sub-channels of different qualities by channelpolarization. Because of the above-described features, a process ofmapping b′ 405 to u 407 may be represented as a sub-channel allocationprocess, and this process may be performed at the encoding inputsequence mapper 406. In some embodiments, among bits of u 407, a bitcorresponding to a sub-channel to which b′ 405 is mapped may be referredto as an unfrozen bit, and a bit corresponding to another sub-channelmay be referred to as a frozen bit. In some embodiments, the unfrozenbit may be fixed to a predetermined value and may be determined ingeneral to be a bit value of zero.

The polar encoder 408 may receive the encoding input bit sequence 407generated at the encoding input sequence mapper 406 and perform polarencoding. That is, the polar encoder 408 may receive the encoding inputbit sequence u 407 from the encoding input sequence mapper 406,polar-encode the received sequence 407, and output a bit sequence 409having the same length. Specifically, the polar encoder 408 may generatean encoding output bit sequence x={x₀, x₁, . . . , x_(N−1)}=uG_(N) 409having the same length N by multiplying the encoding input bit sequenceu 407 having the length N with a generator matrix G of a polar code.Generally, the generator matrix G of the polar code may be defined asEquation 1.G _(N) =B _(N) F ^(⊗ log) ² ^(N)  Equation 1

In Equation 1, G_(N) denotes a generator matrix, F denotes a matrix

${F = \begin{bmatrix}1 & 0 \\1 & 1\end{bmatrix}},$N denotes the size of a mother code of a polar code, and a superscriptoperation ⊗n denotes a Kronecker power of n times. For example,

$F^{\otimes 2} = {{\begin{bmatrix}F & 0 \\F & F\end{bmatrix}{and}F^{\otimes 3}} = {\begin{bmatrix}F^{\otimes 2} & 0 \\F^{\otimes 2} & F^{\otimes 2}\end{bmatrix}.}}$Also, B_(N) denotes a bit-reversal permutation matrix having a size N×N.For example, {a₀, a₄, a₂, a₆, a₁, a₅, a₃, a₇} may be obtained bymultiplying {a₀, a₁, a₂, a₃, a₄, a₅, a₆, a₇} by B₈. However, a generatormatrix having a simple form except for B₈, which has been recently usedin various documents and systems including the 3GPP NR, may be definedas Equation 2.G _(N) =F ^(⊗ log) ² ^(N)  Equation 2

In Equation 2, G_(N) denotes a generator matrix, F denotes a matrix

${F = \begin{bmatrix}1 & 0 \\1 & 1\end{bmatrix}},$N denotes the size of a mother code of a polar code, and a superscriptoperation ⊗n denotes a Kronecker power of n times. In embodiments to bedescribed later, unless otherwise indicated, a generator matrix isassumed to be G_(N)=F^(⊗ log) ² ^(N). The description based on thisassumption may be easily applied to a polar code using a generatormatrix defined as G_(N)=B_(N)F^(⊗ log) ² ^(N) on the basis of thebit-reversal permutation operation. The generator matrix multiplicationmay be implemented in various ways that can output the same result.

The rate matcher 410 may output the output bit sequence 409 of the polarencoder 408 as a bit sequence. That is, the rate matcher 410 may receivethe output bit sequence x 409 from the polar encoder 408 and output abit sequence 411 of a length E to be transmitted. The length to betransmitted for the i-th segment (0≤i<C, C is the number of segments) isE_(i). However, only one segment is described for convenience ofexplanation, so that the output bit length of the rate matcher 410 willbe described as E. In some embodiments, a process of generating a bitsequence of a length E to be transmitted from the coded output bitsequence x may be referred to as a rate matching. In some embodiments, atransmission bit sequence obtainable through such a rate matching may beexpressed as c={c₀, c₁, . . . , c_(B−1)}. In some embodiments, the ratematcher 410 may rearrange the coded output bit sequence x 409 to improvethe coding and decoding performance of a polar code. For example, in the3GPP Release-15 NR, the coded output bit sequence of a polar code x 409may be interleaved in 32 sub-block units and rearranged as x′={x′₀, x′₁,. . . , x′_(N−1)}. In addition, the rate matcher 410 may store therearranged sequence x′ in a circular buffer and generate a codewordsequence of a length E by sequentially extracting the sequence x′ from apredetermined bit position.

A detailed operation of the rate matcher 410 is as follows. In someembodiments, when the length E of the codeword is greater than the sizeN of the mother code of the polar code, the rate matcher 410 may performa repetition operation. In some embodiments, when the length E of thecodeword is less than the size N of the mother code of the polar code,the rate matcher 410 may perform one of a puncturing operation or ashortening operation. In some embodiments, due to a punctured orshortened bit in the sub-channel allocation process of the encodinginput sequence mapper 406, some sub-channels may not be allocated forinformation bits. The shortening process of the rate matcher 410 mayinclude a process of mapping the frozen bit to predetermined bits in theinput bit sequence u 407 of the polar code such that predetermined bitsin the coded output bit sequence x 409 become ‘0’. In some embodiments,the rate matcher 410 may not transmit predetermined bits of ‘0’ in thecoded output bit sequence x 409. In the puncturing process, the ratematcher 410 may puncture predetermined bits in the output bit sequence x409 of the encoding input sequence mapper 406 and not transmit thepunctured bits. Based on the position of a predetermined bit nottransmitted in the output bit sequence x 409, the rate matcher 410 maymap the frozen bit to zero-capacity bits incapable of deliveringinformation in the input bit sequence u 407 of the polar code.

Output bits 411 of the rate matcher 410 are inputted to the segmentconcatenator 412, and coded segments are concatenated to output d={d₀,d₁, . . . d_(B−1)} 413. If necessary, in addition to concatenation ofthe output bit sequences 411 of the rate matcher 410, padding ofpredetermined bits, e.g., zero bits, may be performed. For example, zerobits may be padded so that B satisfies a multiple of the modulationsymbol order. The B value is the number of bits by which the informationbit sequence is transmitted in the system, and may be a predeterminedvalue based on the code rate or the number of modulation symbols.

The above-described encoding process of the polar code is exemplaryonly. Based on the requirements and characteristics of the system, apart of the process may be omitted, or any additional operation may beadded.

FIG. 5 illustrates a functional configuration of a reception-endapparatus that performs decoding in a wireless communication systemaccording to various embodiments of the disclosure. The configurationshown in FIG. 5 may be understood as a part of the communication circuit310 of the reception-end apparatus 120 shown in FIGS. 1 and 3 .

Referring to FIG. 5 , the reception-end apparatus 120 may include a ratedematcher 502, a polar decoder (or an outer-code-aided SC list decoder)504, a message bit extractor 506, and a segment concatenator 508.

In some embodiments, some of the above components may be omitted or anyother component may be added, based on system requirements or the like.

Although not explicitly disclosed herein, the reception-end apparatus120 may include a demodulated log-likelihood ratio (LLR) generator insome embodiments. The demodulated LLR generator may demodulate areceived signal and obtain an LLR corresponding to bits c transmittedfrom the transmission-end apparatus. In some embodiments, an LLRsequence corresponding to the transmission bit sequence c may beexpressed as l={l₀, l₁, . . . , l_(B−1)}.

The rate dematcher 502 inversely performs the rate matching process ofthe transmission-end apparatus 110 in order to input the LLR sequence l′503 generated through the demodulated LLR generator into the polardecoder 504. That is, the rate dematcher 502 may perform an inverseprocess of the rate matching performed by the transmission-end apparatus110 in order to input the LLR sequence l 501 of a length E into thepolar decoder 504 having a mother code of a length N. In someembodiments, when puncturing occurs in the rate matcher 410 of thetransmission-end apparatus, the rate dematcher 502 may determine the LLRvalue for the punctured bit to be zero. In some embodiments, whenshortening occurs in the rate matcher 410 of the transmission-endapparatus, the rate dematcher 502 may determine the LLR value for theshortened bit to be the maximum value of the LLR value corresponding tothe bit value 0. In some embodiments, when repetition occurs for aparticular bit, the rate dematcher 502 may combine all of thecorresponding LLR values and thereby determine the LLR value for the bitwhere the repetition occurs. In some embodiments, an LLR sequence of alength N determined through the above process may be referred to asl′={l′₀, l′₁, . . . , l′_(N−1)} 503.

The polar decoder (or outer-code-aided SC list decoder) 504 may decodethe LLR sequence 503, generated by the rate dematcher 502, through adecoding technique based on SC of a polar code. For example, the polardecoder 504 may perform the polar code SC-based decoding with respect tothe LLR sequence 503 of a length N generated through the rate dematcher502. In various embodiments, the SC-based decoding technique may includean SCL decoding technique or an SCS decoding technique. Variousembodiments to be described below may be implemented in consideration ofthe SCL decoding. However, the disclosure is not limited to a specificdecoding technique such as the SCL decoding technique. In someembodiments, when there are one or more concatenated outer codes, thepolar decoder 504 may improve the SCL decoding performance by using aparity bit of the concatenated outer code during or after the SCLdecoding. In some embodiments, through the above-described decoding, thepolar decoder 504 may output an estimated value û 505 of the encodinginput bit sequence u′ from the transmission-end apparatus 110.

The message bit extractor 506 may extract a message bit at apredetermined position from the estimated value 505 of the encodinginput bit sequence 505 outputted from the polar decoder 504. That is,the message bit extractor 506 may obtain a message bit at apredetermined position from the estimated encoding input bit sequence û505. A message bit sequence extracted through the operation of themessage bit extractor 506 may be referred to as {circumflex over (b)}507.

The segment concatenator 508 inversely performs the segment process ofthe transmission-end apparatus 110. The segment concatenator 508concatenates the output bits 507 of the message bit extractor 506, basedon whether or not the segmentation is performed from the message bits ofthe predetermined position outputted from the message bit extractor 506.The segment concatenator 508 thus may output the concatenated outputbits 509.

The above-described decoding process of the polar code is exemplaryonly. Based on the requirements and characteristics of the system, apart of the process may be omitted, or any additional operation may beadded.

FIG. 6 is a diagram illustrating a polar coding process in a wirelesscommunication system according to various embodiments of the disclosure.

Referring to FIG. 6 , now, the polar coding process will be described inmore detail with reference to FIG. 6 . FIG. 6 shows a polar codingmethod considering segmentation. When it is determined that segmentationis required according to a predetermined condition, an information bitsequence 600 is segmented into C segments (601). The length of each i-thsegment (0≤i<C) is denoted by K_(i) and determined by a predeterminedmethod. Each i-th segment is subjected to outer coding, e.g., CRCencoding (602). The outer-coded output bit sequence is polar-codedthrough polar encoding and rate matching (603). The polar coded segmentsare concatenated to finally generate a concatenated polar coded bitsequence (604). The length E of the concatenated polar coded bitsequence may be

$E = {\left\lceil {\sum\limits_{i = 0}^{C - 1}{E_{i}/m}} \right\rceil \times m}$to satisfy a multiple of the order of modulation symbols, and zero maybe padded by

$\left( {E - {\sum\limits_{i = 0}^{C - 1}E_{i}}} \right)$after concatenation of the polar coded bit sequence. The above length Eis the same as the output bit sequence length B of the segmentconcatenator shown in FIG. 4 . Also, the length E may be a predeterminedvalue obtained by converting the number of modulation symbols fortransmission of the input bit sequence into the number of bits. In oneexample, the number of modulation symbols for transmission of the inputbit sequence may be predetermined by a given condition. In anotherexample, it may be determined based on a predetermined code rate.Therefore, the number of encoding bits E_(i) of each segment and thenumber of zero padding bits may be determined, if necessary, based onthe predetermined E, the presence or absence of segments, and the numberof segments.

Hereinafter, a condition for performing segmentation, which is anoperation of the segmentation 402, and a method for determining thenumber of segments will be described in detail.

FIG. 7 is a diagram illustrating polar coding and segmentation in awireless communication system according to various embodiments of thedisclosure.

Referring to FIG. 7 , first, an encoding method of the polar code and aneed for segmentation will be described with reference to FIG. 7 . InFIG. 7 , the polar encoder, an input bit sequence u={u₀, u₁, . . . ,u_(N−1)} of the polar encoder, and an output bit sequence x={x₀, x₁, . .. , x_(N−1)}=uG_(N) of the polar encoder are shown. When the above N islarger, the encoding/decoding complexity is increased. Thus, the maximumvalue N_(max) of N needs to be set. The lengths N of the input bitsequence and the output bit sequence are determined by a predeterminedmethod according to the length of the information bit sequence, the coderate, and the codeword length. The length N of the output bit sequencecannot be greater than the predetermined N_(max). In some embodiments,when the codeword length E is greater than the mother code size N of thepolar code, repetition is needed. In case of repetition, there is alimit to obtain an encoding performance gain. Thus, when the codewordlength E is larger, segmentation is performed and respective segmentsare encoded with different codewords to reduce the number of repeatedbits and thereby improve performance. When the length of the input bitis small, performance degradation due to repetition does not occur.Therefore, even though the value of E is larger in case of a smalllength of the input bit, the performance may be better when thesegmentation is not performed.

FIG. 8 is a diagram illustrating decoding performance in a wirelesscommunication system according to various embodiments of the disclosure.

Referring to FIG. 8 , FIG. 8 shows required E_(b)/N_(o) for a decodingerror probability of 10⁻² with respect to the input bit length from 1 to550 in case of performing segmentation according to each coding rate andin case of performing no segmentation. As shown in FIG. 8 , when thelength of the information bit sequence is larger than a specific length(e.g., 360), and when the codeword length is larger than a specificlength (e.g., 1088), performing the segmentation has better decodingperformance than performing no segmentation.

Therefore, when A≥A_(th) and E≥E_(th), segmentation with two segments isperformed, and each segment is CRC-coded and polar-coded. For example,in the 3GPP Release-15 NR where N_(max) is 1024, A_(th) is 360 andE_(th) is 1088.

As mentioned above, because the encoding/decoding complexity isincreased when the N is larger, the N cannot exceed the predeterminedN_(max) in consideration of the performance and complexity of thesystem. When the sum of the information bit length A and the number ofparity bits of outer coding (e.g., the number of CRC bits, n_(crc)) isgreater than N_(max), it is needed to perform segmentation.

Further, in order to improve the performance of the system, varioussegmentation criteria and the number of segments may be set as in thefollowing embodiments.

It is possible to determine the number of segments, C, based on thelength, A, of the information bit sequence and the number, E, ofcodeword bits, as follows.

First Embodiment c = C_(max) while c ≥ 1  if {A ≥ f_(th,c)(A_(th,c), c)and E ≥ g_(th,c)(E_(th,c), c)} or A ≥ h_(th,c)(N_(max), c)   C = c  end else c = c − 1 end

In the above, A denotes the length of the input bit sequence, and Edenotes the number of polar encoding bits, i.e., the bit length afterconcatenation of coded segments (including a padding bit, if necessary)when segmentation is required. The above f_(th,c)(A_(th,c),c) is afunction having, as input values, A_(th,c) which is a threshold valuerelated to the length of an information bit sequence for determining thenecessity of segmentation and the number of segments, and the number, c,of segments. The A_(th,c) may vary depending on the number, c, ofsegments. Also, the function f_(th,c) may vary depending on the number,c, of segments. The above g_(th,c)(E_(th,c),c) is a function having, asinput values, E_(th,c) which is a threshold value related to the lengthof a polar encoding bit sequence for determining the necessity ofsegmentation and the number of segments, and the number, c, of segments.The function g_(th,c) may also vary depending on the number, c, ofsegments. The above h_(th,c)(N_(max),c) is a function having, as inputvalues, the maximum size of the mother code and the number, c, ofsegments. The function h_(th,c) may also vary depending on the number ofsegments c.

Hereinafter, detailed embodiments will be described. The number ofcodeword transmission bits, E, is a value determined based on the numberof modulation symbols for transmission of an input bit sequence coded,and the number of modulation symbols may be determined depending on atransmission method. For example, when an input bit sequence is uplinkcontrol information (UCI) and multiplexed with other UCI or data bits,and when E is smaller than the E_(th) bit according to the priority ofthe modulation symbol mapping, but A is larger than the sum of themaximum value of the mother code and the number of CRC code parity bits,segmentation is required. When the length of the input bit sequence islarger than the length excluding the number of parity bits of the outercode from the maximum length of the mother code, and when segmentationis not performed, the polar encoding cannot be performed because the sumof the length of the input bit sequence and the parity bits of the outercode are larger than the maximum length of the mother code.

In the second embodiment, the segmentation is performed in the followingcases.

Second Embodiment

When A≥A_(th) and E≥E_(th), or when A≥(N_(max)−n_(out)), thesegmentation is performed. In this case, the number of segments is two.

In the above, A denotes the length of the input bit sequence, and Edenotes the number of polar encoding bits, i.e., the bit length afterconcatenation of coded segments (including a padding bit, if necessary)when segmentation is required. Also, N_(max) denotes the maximum lengthof the mother code, and n_(out) denotes the number of parity bits of theouter code, e.g., the number of CRC bits. In another embodiment, it maybe the sum of the CRC code and the parity check (PC) bit. For example,when A_(th) is 360, E_(th) is 1088, N_(max) is 1024, and n_(out) is 11,whether to perform segmentation is determined and also the number ofsegments, i.e., the number of polar codes, is determined by thefollowing condition.

When A≥360 and E≥1088, or when A≥(1024−11)=1013, the segmentation isperformed. In this case, the number of segments is two.

In the second embodiment, A≥(N_(max)−n_(out)) related to the input bitsequence length may be changed to A≥α·(N_(max)−n_(out)). Here, α is anumber is smaller than or equal to 1, and it is possible to consider themaximum code rate transmittable when the length of the input bitsequence is the maximum. The condition, A≥(N_(max)−n_(out)), is neededwhen the code rate is very high at the maximum length becauseA≥(N_(max)−n_(out)) but E<E_(th). Therefore, when E<E_(th) and the coderate is very high, the maximum length of the input bit sequence may belimited.

In the above embodiments, the number of segments, that is, the number ofcode words is two. Hereinafter, various embodiments are described.

A method for determining the number of segments and whether to performsegmentation, based on a predetermined reference value according to thenumber of segments is described.

Third Embodiment

When A≥(C−1)×A_(th,C) and E≥(C−1)×E_(th,C), or whenA≥(C−1)×(N_(max)−n_(out)), the segmentation is performed. In this case,the number of segments is C.

In the above, A denotes the length of the input bit sequence, and Edenotes the number of polar encoding bits, i.e., the bit length afterconcatenation of coded segments (including a padding bit, if necessary)when segmentation is required. Also, N_(max) denotes the maximum lengthof the mother code, and n_(out) denotes the number of parity bits of theouter code, e.g., the number of CRC bits. In another embodiment, it maybe the sum of the CRC code and the PC bit.

In the third embodiment, the condition, A≥(C−1)×(N_(max)−n_(out)), maybe omitted in some cases, for example, when the maximum length of theinput bit sequence is smaller than (N_(max)−n_(out)).

More specifically, the fourth embodiment is described hereinafter.

Fourth Embodiment if A ≥ 360 × 3 and E ≥ 1088 × 3  number of segment C =4 else if A ≥ 360 × 2 and E ≥ 1088 × 2  number of segment C =3 else if A≥ 360 and E ≥ 1088  number of segment C = 2 else  number of segment C =1end

In the above, A denotes the length of the input bit sequence, and Edenotes the number of polar encoding bits, i.e., the bit length afterconcatenation of coded segments (including a padding bit, if necessary)when segmentation is required.

FIG. 9 is a diagram illustrating performance variations at various coderates in a wireless communication system according to variousembodiments of the disclosure.

Referring to FIG. 9 , FIG. 9 shows a signal-to-noise ratio (SNR)satisfying a block error rate (BLER)=10⁻² in the additive white Gaussiannoise (AWGN) channel with respect to code rates 2/3, 1/2, 2/5, 1/3, 1/5,1/6, and 1/8 when the length of the information bit sequence ranges from20 bits to 1600 bits. The dotted line represents the performance whenthe maximum number of segments is limited to 2, and the solid lineindicates the third embodiment in which the maximum number of segmentsis 4. As shown in FIG. 9 , when the information word length is larger orthe code rate is lower, that is, when the codeword length is larger, thesame error probability may be achieved by using lower SNR when using thethird embodiment. Therefore, when the information word length is largeror the code rate is lower, that is, when the codeword length is larger,suitably determining the number of segments and performing segmentationcan improve the performance of the system. The improvement in theperformance of the system means that because the use of the thirdembodiment can achieve a lower error probability based on the same SNRwhen using the same code rate, it is possible to use a higher code rateand send more information. Also, because a lower SNR is required whenthe same error is achieved by using the same code rate, it is possibleto transmit the same data to a wider area.

In case of considering the maximum mother code, N_(max), and the paritylength of the outer code, n_(out), in the fourth embodiment, thecondition and the number of segments may be determined as in the fifthembodiment below.

Fifth Embodiment if A ≥ 360 × 3 and E ≥ 1088 × 3 } or A ≥ 3 × (1024 −11) = 3039  number of segment C = 4 else if {A ≥ 360 × 2 and E ≥ 1088 ×2} or A ≥ 2 × (1024 − 11) = 2026  number of segment C =3 else if {A ≥360 and E ≥ 1088} or A ≥ 1 × (1024 − 11) = 1013  number of segment C = 2else  number of segment C =1 end

In the above, A denotes the length of the input bit sequence, and Edenotes the number of polar encoding bits, i.e., the bit length afterconcatenation of coded segments (including a padding bit, if necessary)when segmentation is required. Also, N_(max) denotes the maximum lengthof the mother code, and n_(out) denotes the number of parity bits of theouter code, e.g., the number of CRC bits. In another embodiment, it maybe the sum of the CRC code and the PC bit.

When the number of segments is generalized, it is possible to determinewhether to perform segmentation and also determine the number ofsegments, based on the sixth and seventh embodiments.

Sixth Embodiment c = C_(max) while c ≥ 1  if {A ≥ A_(th) × (c − 1) and E≥ E_(th) × (c − 1) }   C = c  end  else c = c − 1 end

Seventh Embodiment c = C_(max) while c ≥ 1  if { A ≥ A_(th) × (c − 1)and E ≥ E_(th) × (c − 1) } or ≥ (N_(max) − n_(out)) ×  (c − 1)   C = c end  else c = c − 1 end

In the above, A denotes the length of the input bit sequence, and Edenotes the number of polar encoding bits, i.e., the bit length afterconcatenation of coded segments (including a padding bit, if necessary)when segmentation is required. Also, N_(max) denotes the maximum lengthof the mother code, and n_(out) denotes the number of parity bits of theouter code, e.g., the number of CRC bits. In another embodiment, it maybe the sum of the CRC code and the PC bit.

The method of determining the segmentation criterion and the number ofsegments may be varied depending on one of the following parameters. Thereference points may be varied depending on the maximum mother codesize. Because the length of repetition causing performance deteriorationand the ratio of the repetition length to the mother code size arevaried depending on the mother code size, the criterion for determiningwhether to perform segmentation and determining the number of segmentsmay be varied according to the maximum size of the mother code. Also,the criterion for determining whether to perform segmentation anddetermining the number of segments may be varied according to at leastone parameter of a use case, a service scenario, a channel type(physical downlink control channel (PDCCH), physical downlink sharedchannel (PDSCH), physical uplink control channel (PUCCH), or physicaluplink shared channel (PUSCH)), and information bit sequence type. Inaddition, because the ratio of necessary repetition bits to the maximumsize of the mother code may be changed according to the maximum value ofthe number of codeword bits (E in FIG. 6 ) after rate matching, thecriterion for determining whether to perform segmentation anddetermining the number of segments may be varied according to the numberof codeword bits after rate matching. When the maximum codeword sizediffers according to at least one parameter of a use case, a servicescenario, a channel type (PDCCH, PDSCH, PUCCH, or PUSCH), andinformation bit sequence, the segmentation criterion may be varied.

FIG. 10 illustrates a flow diagram of a transmission-end apparatus thatperforms encoding by using a polar code in a wireless communicationsystem according to various embodiments of the disclosure. FIG. 10 showsan operation method of the transmission-end apparatus 110 of FIG. 1 .Operations 1003 to 1008 of FIG. 10 to be described below correspond tooperations of the above-described components 402 to 412 of FIG. 4 ,respectively.

Referring to FIG. 10 , at operation 1001, the transmission-end apparatusinputs a sequence of information bits.

At operation 1002, the transmission-end apparatus performs segmentation,based on whether to perform segmentation, and based on the number ofsegments which are determined according to various embodiments of thedisclosure.

At operation 1003, the transmission-end apparatus performs outer codingon each of the segments. That is, the transmission-end apparatus mayencode the input bit sequence to improve the performance of the ML-likedecoder. In some embodiments, the outer code used for outer coding mayinclude an error detection code such as a CRC code or an errorcorrection code such as a BCH code and a parity check code. In someembodiments, the outer coding process may be omitted depending on theperformance and type of the system.

At operation 1004, the transmission-end apparatus performs encodinginput sequence mapping. For example, the transmission-end apparatus maymap the information bit sequence to an encoding input bit sequence of apolar code, based on the number of information bits, the specificsub-channel order based on sub-channel characteristics of the polarcode, the number of transmission bits, a rate matching method, and thelike.

At operation 1005, the transmission-end apparatus performs polar codeencoding. That is, the transmission-end apparatus may perform encodingof the polar code, based on the encoding input bit sequence to which theinformation bit sequence is mapped. In some embodiments, the encoding ofthe polar code may be performed by multiplying the encoding input bitsequence by a generator matrix.

At operation 1006, the transmission-end apparatus performs ratematching. For example, the transmission-end apparatus may perform therate matching by performing puncturing, shortening, or repetition, basedon the number of information bits and the number of transmission bits.

At operation 1007, the transmission-end apparatus performs aconcatenation on the segments. When no segmentation is performed, theoperation 1007 may not be performed.

At operation 1008, the transmission-end apparatus performs datatransmission. That is, the transmission-end apparatus may modulate therate-matched bit sequence and transmit it to a reception-end apparatus.

FIG. 11 illustrates a flow diagram of a reception-end apparatus thatperforms decoding by using a polar code in a wireless communicationsystem according to various embodiments of the disclosure. FIG. 11 showsan operation method of the reception-end apparatus 120 of FIG. 1 .Operations 1101 to 1106 of FIG. 11 to be described below correspond tooperations of the above-described components 502 to 508 of FIG. 5 ,respectively.

Referring to FIG. 11 , at operation 1101, the reception-end apparatusreceives a signal. That is, the reception-end apparatus may receiveencoded signals through a channel from a transmission-end apparatus.

At operation 1102, the reception-end apparatus performs demodulation. Insome embodiments, the reception-end apparatus may demodulate thereceived signal and, based on the received signal, determine an LLRvalue which is a logarithm ratio between a probability that the value ofa bit transmitted by the transmission-end apparatus was zero and aprobability that it was one.

At operation 1103, the reception-end apparatus performs rate dematching.That is, the reception-end apparatus may inversely perform a ratematching process performed by the transmission-end apparatus beforeperforming polar code decoding. For example, the reception-end apparatusmay determine an LLR value corresponding to related bits according to apuncturing, shortening, or repetition technique determined based on thenumber of input bits and the number of transmission bits.

At operation 1104, the reception-end apparatus performs the polar codedecoding. For example, the reception-end apparatus may output anestimated value for the encoding input bit sequence through SC-baseddecoding based on the LLR value determined through the rate dematchingprocess. In some embodiments, the SC-based decoding technique mayinclude an SCL or SCS decoding technique.

At operation 1105, the reception-end apparatus performs message bitextraction. For example, the reception-end apparatus may extract amessage bit at a predetermined position from the estimated value of theencoding input bit sequence outputted through the polar code decoding.

At operation 1106, the reception-end apparatus performs desegmentation,based on whether the segmentation is performed, and based on the numberof segments according to various embodiments of the disclosure.

Referring to the above descriptions about FIGS. 1 to 11 , the apparatusand method according to various embodiments of the disclosure may changea specific parameter to define encoding of the transmission-endapparatus and decoding of the reception-end apparatus when performingthe encoding and decoding of the polar code by using a concatenatedouter code including a parity check bit.

FIG. 12 illustrates a functional configuration of a reception-endapparatus that performs decoding in a wireless communication systemaccording to various embodiments of the disclosure. The configurationshown in FIG. 12 may be understood as a part of the communicationcircuit 310 of the reception-end apparatus 120 shown in FIGS. 1 and 3 .

Referring to FIG. 12 , the reception-end apparatus 120 may include ademodulator 1202, a segmentation 1204, a rate dematcher (orderatematcher) 1206, a polar decoder (or an outer-code-aided SC listdecoder) 1208, a message bit extractor 1210, and a segment concatenator1212 according to various embodiments of the disclosure.

In some embodiments, some of the above components may be omitted or anyother component may be added, based on system requirements or the like.

The demodulator 1202 demodulates a received signal 1201 to obtain an LLRcorresponding to a bit, d, transmitted from the transmission-endapparatus. In some embodiments, the LLR sequence corresponding to thetransmission bit sequence, d, may be expressed as r={r₀, r₁, . . . ,r_(E)} 1203.

The segmentation 1204 obtains the LLR corresponding to the transmissionbit sequence, c, based on whether the segmentation is performed in thetransmission-end apparatus 110 and based on the number of segments, inorder to input the LLR sequence 1203 generated through the demodulator1202 into the rate dematcher 1206. In some embodiments, the LLR sequencecorresponding to the transmission bit sequence, c, may be represented byl={l₀, l₁, . . . , l_(E)} 1205. When the transmitted bit sequence is thei-th segment (0≤i<C), E is E_(i). The E_(i) is the number of polar codedbits of the i-th segment and may be determined according to apredetermined scheme. Whether the segmentation is performed and thenumber of segments can be determined based on the embodiments of thedisclosure and operate accordingly.

The rate dematcher 1206 inversely performs the rate matching process ofthe transmission-end apparatus 110 in order to input the LLR sequencegenerated through the demodulated LLR generator into the polar decoder1208. That is, the rate dematcher 1206 may perform an inverse process ofthe rate matching performed by the transmission-end apparatus 110 inorder to input the LLR sequence l 1205 of a length E into the polardecoder 1208 having a mother code of a length N. In some embodiments,when puncturing occurs in the rate matcher 410 of the transmission-endapparatus, the rate dematcher 1206 may determine the LLR value for thepunctured bit to be zero. In some embodiments, when shortening occurs inthe rate matcher 410 of the transmission-end apparatus, the ratedematcher 1206 may determine the LLR value for the shortened bit to bethe maximum value of the LLR value corresponding to the bit value 0. Insome embodiments, when repetition occurs for a particular bit, the ratedematcher 1206 may combine all of the corresponding LLR values andthereby determine the LLR value for the bit where the repetition occurs.In some embodiments, an LLR sequence of a length N determined throughthe above process may be referred to as l′={l′₀, l′₁, . . . , l′_(N−1)}1207.

The polar decoder (or outer-code-aided SC list decoder) 1208 may decodethe LLR sequence 1207, generated by the rate dematcher 1206, through adecoding technique based on SC of a polar code. For example, the polardecoder 1208 may perform the polar code SC-based decoding with respectto the LLR sequence 1207 of a length N generated through the ratedematcher 1206. In various embodiments, the SC-based decoding techniquemay include an SCL decoding technique or an SCS decoding technique.Various embodiments described herein may be implemented in considerationof the SCL decoding. However, the disclosure is not limited to aspecific decoding technique such as the SCL decoding technique. In someembodiments, when there is one or more concatenated outer codes, thepolar decoder 1208 may improve the SCL decoding performance by using aparity bit of the concatenated outer code during or after the SCLdecoding. In some embodiments, through the above-described decoding, thepolar decoder 1208 may output an estimated value û 1209 of the encodinginput bit sequence u′ from the transmission-end apparatus 110.

The message bit extractor 1210 may extract a message bit at apredetermined position from the estimated value of the encoding inputbit sequence outputted from the polar decoder 1208. That is, the messagebit extractor 1210 may obtain a message bit at a predetermined positionfrom the estimated encoding input bit sequence û 1209. A message bitsequence extracted through the operation of the message bit extractor1210 may be referred to as {circumflex over (b)} 1211.

The segment concatenator 1212 inversely performs the segment process ofthe transmission-end apparatus 110. The segment concatenator 1212concatenates the output bits of the message bit extractor 1210, based onthe number of segments. The segment concatenator may thus output theconcatenated segments 1213.

The above-described decoding process of the polar code is exemplaryonly. Based on the requirements and characteristics of the system, apart of the process may be omitted, or any additional operation may beadded.

FIG. 13 illustrates a flow diagram of a reception-end apparatus thatperforms decoding by using a polar code in a wireless communicationsystem according to various embodiments of the disclosure. FIG. 13 showsan operation method of the reception-end apparatus 120 of FIG. 1 .Operations 1301 to 1307 of FIG. 13 to be described below correspond tooperations of the above-described components 1202 to 1212 of FIG. 12 ,respectively.

Referring to FIG. 13 , at operation 1301, the reception-end apparatusreceives a signal. That is, the reception-end apparatus may receiveencoded signals through a channel from a transmission-end apparatus.

At operation 1302, the reception-end apparatus performs demodulation. Insome embodiments, the reception-end apparatus may demodulate thereceived signal and, based on the received signal, determine an LLRvalue which is a logarithm ratio between a probability that the value ofa bit transmitted by the transmission-end apparatus was zero and aprobability that it was one.

At operation 1303, the reception-end apparatus performs segmentation,depending on whether the segmentation is performed, and based on thenumber of segments. Whether or not the segments are segmented and thenumber of segments can be determined and operated are based on theembodiments of the disclosure.

At operation 1304, the reception-end apparatus performs rate dematching.That is, the reception-end apparatus may inversely perform a ratematching process performed by the transmission-end apparatus beforeperforming polar code decoding. For example, the reception-end apparatusmay determine an LLR value corresponding to related bits according to apuncturing, shortening, or repetition technique determined based on thenumber of input bits and the number of transmission bits.

At operation 1305, the reception-end apparatus performs the polar codedecoding. For example, the reception-end apparatus may output anestimated value for the encoding input bit sequence through SC-baseddecoding based on the LLR value determined through the rate dematchingprocess. In some embodiments, the SC-based decoding technique mayinclude an SCL or SCS decoding technique.

At operation 1306, the reception-end apparatus performs message bitextraction. For example, the reception-end apparatus may extract amessage bit at a predetermined position from the estimated value of theencoding input bit sequence outputted through the polar code decoding.

At operation 1307, the reception-end apparatus performs desegmentation,based on whether the segmentation is performed, and based on the numberof segments according to various embodiments of the disclosure.

Referring to the above descriptions about FIGS. 12 and 13 , theapparatus and method according to various embodiments of the disclosuremay change a specific parameter to define encoding of thetransmission-end apparatus and decoding of the reception-end apparatuswhen performing the encoding and decoding of the polar code by using aconcatenated outer code including a parity check bit.

Meanwhile, embodiments described above with reference to FIGS. 1 to 13can be applied to the following processes.

In the uplink transmission process of long term evolution (LTE)/LTEadvanced (LTE-A), information bits transmitted on an uplink sharedchannel (UL-SCH) of a transmission channel are divided into units of atransport block (TB), and a TB CRC bit is added. Then, the TB+TB-CRCbits are divided into at least one code block (CB), and a CB-CRC isadded. Then, the CB+CB-CRCs are mapped to a PUSCH by passing throughprocedures such as channel coding, rate matching (RM), and code blockconcatenation (CBC).

An uplink control channel (or UCI) of the transmission channel may becomposed of UCI elements such as a hybrid automatic repeat request(HARQ) or rank indicator (RI), a channel state information (CSI)reference signal (CSI-RS) resource indicator (CRI), a precoding matrixindicator (PMI), and a channel quality indicator (CQI). Channel codingmay be applied individually or through joint encoding of one or more UCIelements according to a predefined rule. The channel coding applied UCImay be multiplexed with the uplink data channel and transmitted on thePUSCH or on a PUCCH.

Meanwhile, in case of the NR system, CBs included in one TB may bedivided into one or more code block groups (CBGs). In some cases, HARQacknowledgment/non-acknowledgment (ACK/NACK) is reported for each CBG,so that retransmission of each CBG is possible. Excepting this, theuplink transmission process of the NR is similar to those of the LTE andLTE-A systems.

In the LTE, LTE-A, and NR systems, a terminal may measure a referencesignal transmitted by a base station in downlink and, based on themeasurement result, feed the generated UCI back to the base station.There are five types of UCI elements that the terminal feeds back.

-   -   CRI: Index of a CSI-RS resource preferred by a terminal among        CSI-RSs transmitted by a base station    -   RI: The number of spatial layers preferred by a terminal in the        current channel state    -   PMI: Indicator for a precoding matrix preferred by a terminal in        the current channel state    -   CQI: This means the maximum data rate that can be received by a        terminal in the current channel state. The CQI may be replaced        by a signal to interference plus noise ratio (SINR), a maximum        error-correcting code rate and modulation scheme, data        efficiency per frequency, etc. which can be utilized similar to        the maximum data rate.    -   CSI reference signal received power (RSRP) or synchronization        signal block (SSB) RSRP: This is the received power for X        CSI-RS(s) designated by CRI or previously agreed (e.g., the        highest received power). The SSB RSRP is the received power for        X SSB(s) indicated by a base station or previously agreed (e.g.,        the highest received power). Here, the received power of the SSB        may be defined as one of a primary SS (PSS), a secondary SS        (SSS), or a physical broadcast channel (PBCH), or as an average        received power of some or all of them.

In case of the NR, a periodic CSI reporting may be transmitted through ashort PUCCH or a long PUCCH. The short PUCCH is a PUCCH format composedof one or two orthogonal frequency division multiplexing (OFDM) symbols,and the long PUCCH is a PUCCH format composed of three or more OFDMsymbols. In the NR, only single-slot reporting is supported for the CSIreporting via the short PUCCH or long PUCCH, and multiplexing of CSIparameters (or UCI elements) between multiple slots as in the LTE andLTE-A is not supported. This can reduce multiple reporting timedependency on one CSI reporting and also prevent performance degradationdue to error propagation.

In the NR system, three types of codebooks are supported. A terminal maybe instructed to use one of three types of codebooks through upper layersignaling. The first type is a type I-single panel codebook that assumesa single panel and a low CSI feedback resolution. The second type is atype I-multi panel codebook that assumes multiple panels and a low CSIfeedback resolution. The third type is a Type II codebook that assumes asingle panel and a high CSI feedback resolution. Also, in the NR, eachtype of codebook may be set to one of two modes. The first mode is amode in which one beam group contains one beam direction. In this case,i2 indicates only co-phasing information. The second mode is a mode inwhich one beam group contains one or more beam directions. In this case,i2 indicates both beam selection and co-phasing information.

In the NR, the Reed-Muller (RM) code is used for channel coding ofdownlink control information (DCI) or UCI information bits of 11 bits orless, and the polar code is used for channel coding of DCI or UCIinformation bits of 12 bits or more. The above information bits may becounted by including only the A-bit UCI bit stream or counted byincluding both the A-bit UCI bit stream and the L-bit parity bits.

Now, the polar code is further described. In the polar code encoding,information bits are encoded by a predetermined generation matrix andthereby converted to codeword. At this time, information bits may havedifferent reliability. Therefore, it is possible to improve decodingperformance by defining some of the bits with low reliability accordingto the order of reliability as a frozen bit, using a predetermined valueand using the remainder as data bits.

Also, in the polar code encoding, it is possible to distinguish a bitindex to be used as a frozen bit and a bit index to be used as a databit according to a desired coding rate (CR) such as CR=1/3, CR=1/2, orCR=3/4. This sequence of the index may be defined as a polar codesequence. Therefore, the above code rate means a code rate before ratematching is applied. That is, the number of coded bits is equal to themother code size of the polar code. When sorting this polar codesequence according to the reliability of each bit, the polar codesequence is divided into a frozen bit part composed of bits having thelowest reliability, a data bit part composed of bits having intermediatereliability, and a CRC part having the highest reliability. In addition,the reliability of the data bit part and the CRC part may not bedistinguished.

Next, the polar code decoding is described. The reception-end apparatusdecodes a received signal based on the generation matrix for the definedpolar code sequence. This decoding is performed in the reverse order ofthe reliability of each information bit by the reception-end apparatuscomposed of a plurality of basic decoding units. In each basic decodingunit, LLR calculation (check node operation) and successive cancelation(variable node operation) for corresponding node are sequentially andcontinuously performed.

A channel coding chain based on the polar code is now described. DCI orUCI is converted to a polar code input sequence (bit sequence) through aCRC encoder. The polar code input sequence is converted to a polarcodeword through a polar code encoder, and then rate matching isperformed. Then, if necessary, the rate-matched codeword ischannel-interleaved in a circular buffer, modulated, and mapped to PDCCHor PUCCH.

In the NR system, for PDCCH and PUCCH channel encoding and decoding, thepolar code is used for information payload. Hereinafter, the encodingand decoding processes based on the NR polar code will be described indetail.

A data/control stream received from a medium access control (MAC) layeror transmitted to the MAC layer is encoded or decoded to providetransport and control services after a radio transmission connection.The channel coding scheme based on the polar code is formed of acombination of error detection, error correction, rate matching,interleaving, and mapping to a physical channel

-   -   CRC calculation process: In an input bit sequence a₀, a₁, a₂,        a₃, . . . , a_(A−1) and parity bits p₀, p₁, p₂, p₃, . . . ,        p_(L−1), A denotes the size of input bit sequence, L denotes the        number of CRC parity bits, and the parity bits are generated        based on cyclic generator polynomial. The cyclic generator        polynomial is defined by a standard specification. A bit        sequence after the CRC parity bit addition becomes b₀, b₁, b₂,        b₃, . . . , b_(B−1), and B=A+L.    -   Code block segmentation and code block CRC addition process:        When segmentation is performed for the input bit sequence a₀,        a₁, a₂, a₃, . . . , a_(A−1) of the code block segmentation, the        number of segmented code blocks, C, is two. Otherwise, the        number of code blocks is one. For each of the segmented code        blocks, parity bits p_(r0), p_(r1), p_(r2), . . . , p_(r(L−1))        are calculated according to the above-described CRC calculation        process, and “r” denotes an index for identifying a segmented        code block.    -   Channel coding process: Different coding schemes are applied to        different types of transport channels (TrCH), and different        coding schemes are applied to different control information. For        example, the polar code is applied to the BCH, the polar code        may be applied to the DCI transmitted on the PDCCH, and the        polar code and the block code may be applied to the UCI        transmitted on the PUCCH or PUSCH. For any code block, the bit        sequence input into channel coding is c₀, c₁, c₂, c₃, . . . ,        c_(K−1), where “K” denotes the number of bits to be coded. The        bit after encoding is d₀, d₁, d₂, . . . , d_(N−1), where N=2^(n)        and “n” is defined by the standard. In the channel coding        process, the bit sequence c₀, c₁, c₂, c₃, . . . , c_(K−1) is        interleaved and becomes c′₀, c′₁, c′₂, c′₃, . . . , c′_(K−1).        The interleaved bits are encoded via the polar code, and the        encoded output is d=[d₀ d₁ d₂ . . . d_(N−1)]. The interleaving        may not be used under every condition. For example, interleaving        may be used for the bit sequence transmitted on the BCH or        PDCCH, and interleaving may not be used for the bit sequence        transmitted on the PUCCH or PUSCH.    -   Rate matching process: The rate matching for the polar code is        defined in units of code blocks and composed of sub-block        interleaving, bit selection (collection), and bit interleaving.        An input into rate matching is d₀, d₁, d₂, . . . , d_(N−1), and        an output bit sequence after the rate matching is f₀, f₁, f₂, .        . . , f_(E−1). The coded bits d₀, d₁, d₂, . . . , d_(N−1)        inputted into the sub-block interleaver are divided into 32        sub-blocks. Output bits from the sub-block interleaver are y₀,        y₁, y₂, . . . , y_(N−1), and sub-block-interleaved according to        the procedure defined in the standard specification. The output        y₀, y₁, y₂, . . . , y_(N−1) from the sub-block interleaver is        written into the cyclic buffer of length N, and an output bit        sequence of the bit selection becomes e_(k). At this time, k=0,        1, 2, . . . , E−1, where “E” denotes the length of the rate        matching output sequence. The bit sequence e₀, e₁, e₂, . . . ,        e_(E−1) is bit-interleaved and then outputted as f₀, f₁, f₂, . .        . , f_(E−1).    -   Code block concatenation process: An input bit sequence into the        code block concatenation process is f_(rk), where r=0, . . . ,        C−1 and k=0, . . . , E_(r)−1. Also, E_(r) denotes the number of        bits for which the rate matching is performed on the r-th code        block. Output bits of the code block concatenation are g_(k),        where k=0, . . . , G−1. The code block concatenation process is        performed by sequentially concatenating the rate matching        results for different code blocks.

Hereinafter, a process of applying the polar code when the UCI istransmitted on the PUCCH or PUSCH will be described.

A terminal generates a UCI bit sequence, and the UCI bit sequence mayinclude HARQ-ACK and/or SR, only CSI, or HARQ-ACK and/or CSI. Code blocksegmentation and CRC addition are performed on the generated UCI bitsequence. In case where the payload size A is equal to or larger than12, if A≥360 and E≥1088, I_(seg)=1, or if A≥1013, I_(seg)=1. In theother cases, I_(seg)=0. If 12≤A≤19, the parity bits p_(r0), p_(r1),p_(r2), . . . , p_(r(L−1)) are calculated by setting L to 6 bits, and ifA≥20, the parity bits p_(r0), p_(r1), p_(r2), . . . , p_(r(L−1)) arecalculated by setting L to 11 bits. When I_(seg)=1, it means that thesegmentation is performed with two segments. When I_(seg)=0, it meansthat segmentation is not performed. The above “E” denotes apredetermined value and is defined in the standard, based on the numberof resource elements (REs) for transmission of UCI, the number oflayers, the modulation order, and the like. The predetermined E value isexpressed as E_(UCI).

Information bits c_(r0), c_(r1), c_(r2), c_(r3), . . . , c_(r(K) _(r)⁻¹⁾ are delivered to the channel coding block, where “r” denotes thecode block number, and K_(r) denotes the number of bits contained in thecode block number “r.” The total number of code blocks is C, and eachcode block is independently coded. The bits encoded through the polarcoding are d_(r0), d_(r1), d_(r2), d_(r3), . . . , d_(r(N) _(r) ⁻¹⁾,where N_(r) is the number of coded bits contained in the code block “r.”The total number of the code blocks, C, is 2 in case of I_(seg)=1, andis 1 in case of I_(seg)=0. The number of the code blocks, C, isexpressed as C_(UCI).

An input bit sequence into the rate matching is d_(r0), d_(r1), d_(r2),d_(r3), . . . , d_(r(N) _(r) ⁻¹⁾, and the rate matching is performedtogether with bit interleaving by setting I_(BIL)=1. The length of arate matching output sequence is E_(r)└E_(UCI)/C_(UCI)┘, where C_(UCI)is the number of code blocks for UCI and is defined together withE_(UCI) by the standard specification. An output bit sequence of therate matching is f_(r0), f_(r1), f_(r2), . . . , f_(r(E) _(r) ⁻¹⁾, whereE_(r) is the length of the rate matching output sequence of the codeblock “r.”

An input bit sequence into the code block concatenation block is f_(r0),f_(r1), f_(r2), . . . , f_(r(E) _(r) ⁻¹⁾, and bits after the code blockconcatenation are expressed by g₀, g₁, g₂, g₃, . . . , g_(G′−1). HereG′└E_(UCI)/C_(UCI)┘·C_(UCI), and G=G′+mod(E_(UCI), C_(UCI)), where G isthe total number of coded bits for transmission, and g_(i)=0 for i=G′,G′+1, . . . , G−1.

The coded UCI bits generated through the above process are transmittedto a base station via the PUCCH or PUSCH.

Hereinafter, a process of applying the polar code when DCI istransmitted on the PDCCH will be described.

A base station generates a DCI bit sequence, and the DCI transmitsdownlink control information for one or more cells by using one radionetwork temporary identifier (RNTI). An encoding operation for the DCImay be performed through information element multiplexing, CRC addition,channel coding, and rate matching.

The DCI format is defined according to usage of each DCI, and issequentially mapped to information bits a₀ to a_(A−1) in fields definedaccording to the DCI format. If necessary, zero padding bits may bemapped to the information bits or truncation may be applied. If thenumber of information bits is less than 12 bits, the zero bit isappended until it becomes 12 bits.

Error detection is provided via CRC for DCI transmission. To calculatethe CRC parity bit, the entire payload may be used. When payload bitsand parity bits are expressed by and a₀, a₁, a₂, a₃, . . . , a_(A−1) andp₀, p₁, p₂, p₃, . . . , p_(L−1), respectively, “A” denotes the payloadsize and “L” denotes the number of parity bits. The parity bits arecalculated by setting L to 24 and are generated according to theprocedure defined by the standard specification. Output bits of the CRCaddition process is b₀, b₁, b₂, b₃, . . . , b_(K−1), where K=A+L. Whenthe CRC is added, the CRC parity bits are scrambled with thecorresponding RNTI.

After the CRC addition, information bits delivered to the channel codingblock is c₀, c₁, c₂, c₃, . . . , c_(K−1), where K is the number of bits.The information bits are encoded through polar coding, n_(max)=9,I_(IL)=1, n_(PC)=0, and n_(PC) ^(wm)=0. Coded bits are d₀, d₁, d₂, d₃, .. . , d_(N−1), where N is the number of coded bits. The above n_(max)=9means that the maximum size of the mother code of the polar code is2⁹=512, I_(IL)=1 means that the information bits are interleaved, andn_(PC)=0 means that the number of parity bits is 0 in the polarencoding.

An input bit sequence into the rate matching is d₀, d₁, d₂, d₃, . . . ,d_(N−1), which is set to I_(BIL)=0 in the rate matching process and isnot bit-interleaved. An output bit sequence after the rate matching isf₀, f₁, f₂, . . . , f_(E−1).

The coded DCI bits generated through the above process are transmittedto a terminal through the PDCCH.

Methods according to claims or embodiments described in the disclosuremay be implemented by hardware or a combination of hardware andsoftware.

When implemented using software, a computer-readable storage medium forstoring one or more programs (software modules) may be provided ashardware. One or more programs stored on the computer-readable storagemedium are configured for execution by one or more processors in anelectronic device. The one or more programs include instructions thatcause the electronic device to perform the methods according to claimsor embodiments described herein.

Such programs (software module, software) may be stored in a randomaccess memory, a non-volatile memory including a flash memory, a readonly memory (ROM), an electrically erasable programmable ROM (EEPROM), amagnetic disc storage device, a compact disc ROM, digital versatilediscs (DVDs) or other optical storage devices, and a magnetic cassette.Alternatively, the programs may be stored in a memory combining part orall of those recording media. A plurality of memories may be equipped.

The programs may be stored in an attachable storage device accessiblevia a communication network formed of Internet, Intranet, local areanetwork (LAN), wide area network (WAN), or storage area network (SAN)alone or in combination. This storage device may access an apparatusperforming embodiments of the disclosure through an external port. Inaddition, a separate storage device in the communication network mayaccess an apparatus performing embodiments of the disclosure.

In the above-described embodiments, components or elements have beenexpressed as a singular or plural form. It should be understood,however, that such singular or plural representations are selectedappropriately according to situations presented for the convenience ofdescription, and the disclosure is not limited to the singular or pluralform. Even expressed in a singular form, a component or element may beconstrued as a plurality of components or elements, and vice versa.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

What is claimed is:
 1. A method of transmitting a signal by atransmitting apparatus in a wireless communication system or abroadcasting system, the method comprising: generating a bit sequence;determining whether to perform a code block segmentation for the bitsequence; segmenting the bit sequence into two segments based on thedetermination; generating coded bits by encoding the two segments; andtransmitting, to a receiving apparatus, the coded bits, wherein thedetermining whether to perform the code block segmentation for the bitsequence comprises: in case that a number of bits of the bit sequence isgreater than or equal to a first value 1013, segmenting the bit sequenceinto two segments, and in case that the number of bits of the bitsequence is greater than or equal to a second value 360 and a length ofa rate matching output sequence is greater than or equal to a thirdvalue 1088, segmenting the bit sequence into two segments.
 2. The methodof claim 1, wherein the bit sequence is for uplink control information(UCI), and wherein the UCI is encoded by using a polar code.
 3. Themethod of claim 1, wherein the first value 1013 is determined based on amaximum length of a mother code, 1024, and a number of cyclic redundancycheck (CRC) parity bits,
 11. 4. The method of claim 1, furthercomprising: determining to perform the code block segmentation for thebit sequence regardless of a length of the rate matching outputsequence, in case that the number of bits of the bit sequence is greaterthan or equal to the first value
 1013. 5. A transmitting apparatus oftransmitting a signal in a wireless communication system or abroadcasting system, the transmitting apparatus comprising: atransceiver configured to transmit and receive a signal; and acontroller coupled with the transceiver and configured to: generate abit sequence, determine whether to perform a code block segmentation forthe bit sequence, segment the bit sequence into two segments based onthe determination, generate coded bits by encoding the two segments, andtransmit, to a receiving apparatus, the coded bits, wherein thedetermining whether to perform the code block segmentation for the bitsequence comprises: in case that a number of bits of the bit sequence isgreater than or equal to a first value 1013, segmenting the bit sequenceinto two segments, and in case that the number of bits of the bitsequence is greater than or equal to a second value 360 and a length ofa rate matching output sequence is greater than or equal to a thirdvalue 1088, segmenting the bit sequence into two segments.
 6. Thetransmitting apparatus of claim 5, wherein the bit sequence is foruplink control information (UCI), and wherein the UCI is encoded byusing a polar code.
 7. The transmitting apparatus of claim 5, whereinthe first value 1013 is determined based on a maximum length of a mothercode, 1024, and a number of cyclic redundancy check (CRC) parity bits,11.
 8. The transmitting apparatus of claim 5, wherein the controller isfurther configured to: determine to perform the code block segmentationfor the bit sequence regardless of a length of the rate matching outputsequence, in case that the number of bits of the bit sequence is greaterthan or equal to the first value
 1013. 9. A non-transitorycomputer-readable storage medium encoded with instructions which, whenexecuted by a transmitting apparatus comprising a processor, cause thetransmitting apparatus to: generate a bit sequence; determine whether toperform a code block segmentation for the bit sequence; segment the bitsequence into two segments based on the determination; generate codedbits by encoding the two segments; and transmit, to a receivingapparatus, the coded bits, wherein the determining whether to performthe code block segmentation for the bit sequence comprises: in case thata number of bits of the bit sequence is greater than or equal to a firstvalue 1013, segmenting the bit sequence into two segments, and in casethat the number of bits of the bit sequence is greater than or equal toa second value 360 and a length of a rate matching output sequence isgreater than or equal to a third value 1088, segmenting the bit sequenceinto two segments.
 10. The storage medium of claim 9, wherein the bitsequence is for uplink control information (UCI), and wherein the UCI isencoded by using a polar code.
 11. The storage medium of claim 9,wherein the first value 1013 is determined based on a maximum length ofa mother code, 1024, and a number of cyclic redundancy check (CRC)parity bits,
 11. 12. The storage medium of claim 9, wherein in case thatthe number of bits of the bit sequence is greater than or equal to thefirst value 1013, it is determined to perform the code blocksegmentation for the bit sequence regardless of a length of the ratematching output sequence.